1. Field of the Invention
The present invention pertains to self-blunting medical needles and, in particular, to needle assemblies that can lock in a blunted configuration.
2. Related Art
Many accidental needle-stick wounds are sustained by healthcare workers each day. The problem is aggravated by the trend of moving treatment out of hospitals and into doctors"" offices and neighborhood clinics as part of programs to reduce healthcare costs. This trend increases the number and dispersion of healthcare workers who administer injections and draw blood samples, while reducing the frequency of such injections per individual healthcare worker. As a consequence, a larger number of less experienced people are administering injections and/or taking blood samples. Although in the past an occasional serious illness such as that caused by the hepatitis B virus was sustained as a result of an accidental needle-stick wound, the problem was not considered to be a serious one until the advent of human immunodeficiency virus (HIV) and the knowledge that this virus is transmissible to healthcare workers through needle-stick wounds from a contaminated needle. HIV causes acquired immune deficiency syndrome (AIDS), a disease, which, insofar as is presently known, is invariably fatal, and which has already killed millions and infected millions more. HIV is often referred to simply as xe2x80x9cthe AIDS virusxe2x80x9d and the Surgeon General of the United States of America noted in a published (September, 1987) interview that there is no better way to become infected with the AIDS virus than to take blood from an AIDS patient and accidentally inflict a needle-stick wound with the contaminated needle.
This situation has stimulated activity to develop devices which reduce or eliminate the possibility of accidental needle-stick wounds without excessively increasing the unit cost of needles.
U.S. Pat. No. 5,176,655 to McCormick et al, dated Jan. 5, 1993 and entitled xe2x80x9cDISPOSABLE MEDICAL NEEDLE AND CATHETER PLACEMENT ASSEMBLY HAVING FULL SAFETY ENCLOSURE MEANSxe2x80x9d, discloses a winged set in which a needle is movably and concentrically disposed within a tubular member to which the wings are attached. The needle is connected to the wings via straps (42). A guard device (50) is carried on the tubular member by a pair of clip legs (56). During use, the needle protrudes through the tubular member and the blocking plate bears on the side of the needle under the force of the spring. After the device has been used, the needle is withdrawn into the tubular member and the blocking plate springs down over the end of the tubular member to permanently prevent the sharp tip of the needle from exiting the tubular member (see column 3, lines 23-29, and column 6, lines 28-36). The tubular member is not adapted for engagement with any other device and no method or mechanism for re-sharpening the winged set is disclosed. Neither the needle nor the blunting member are fully enclosed one within the other.
U.S. Pat. No. 4,627,841, issued to Dorr on Dec. 9, 1986 and entitled xe2x80x9cINFUSION NEEDLExe2x80x9d, discloses a winged venipuncture set in which a needle is movably mounted within a catheter. A spring biases the catheter forward so that it protrudes beyond the tip of the needle and the device is configured so that when grasped for use, the catheter is withdrawn against the bias of the spring to sharpen the needle until the device is released. No locking mechanism for keeping the catheter in one position or the other is shown.
U.S. Pat. No. 5,743,882, issued to Luther on Apr. 28, 1998 and entitled xe2x80x9cNEEDLE BLUNTING ASSEMBLY FOR USE WITH INTRAVASCULAR INTRODUCERSxe2x80x9d, discloses a non-automatic manual needle blunting assembly which features a blunting member disposed telescopically within the passageway of a needle or cannula and manually axially movable from a xe2x80x9cnon-bluntingxe2x80x9d position to a xe2x80x9cbluntingxe2x80x9d position. In alternative embodiments, the blunting member is held in place by screw threads or elastomeric fins within a chamber defined by the needle member. The referenced needle is neither automatic in operation nor lockable, the user manually advances or retreats the blunting assembly and the positioning can be altered by an accidental bump.
U.S. Pat. No. 5,374,252 to Banks et al, dated Dec. 20, 1994 and entitled xe2x80x9cLOCKING PNEUMONEEDLExe2x80x9d, discloses a pneumoneedle used for introducing an insufflating gas into the abdominal cavity of a patient via the fluid conduit. The device comprises a cannula (20) (FIG. 1) mounted in a housing (12). The housing (12) also contains a tubular protector (or xe2x80x9cblunting memberxe2x80x9d) (31) disposed within the cannula and movable between a retracted position in which the sharp tip of the cannula is exposed and a deployed position in which the blunt end (32) of the protector extends beyond the sharp tip of the cannula. The protector (31) is tubular and has a distal aperture (36) that is exposed when the protector is moved to the deployed position. There is also a proximal aperture (35) that opens to an internal fluid passageway portion of the housing (12). A fluid conduit (8) (FIG. 2) in the housing communicates with fluid passageway portion (18) and extends at an angle relative to the longitudinal axis of the needle cannula.
In the medical field, pneumoneedles such as those disclosed by Banks et al are considered to serve a function that is disparate from that of intravenous fluid flow devices and the knowledge in the art pertaining to pneumoneedles is not seen as analogous or pertinent to intravenous needles.
U.S. Pat. No. 5,250,036, issued to Farivar on Oct. 5, 1993 and entitled xe2x80x9cINTRAVENOUS CATHETER PLACEMENT SYSTEMxe2x80x9d, teaches an intravenous catheter placement system having an external insertion guard tool assembly and a flexible catheter with an attachment at one end. Farivar does not teach a releasable locking mechanism.
U.S. Pat. No. 5,462,533, issued to Daugherty on Oct. 31, 1995 and entitled xe2x80x9cSELF CONTAINED NEEDLE AND SHIELDxe2x80x9d, teaches a design having a cannula made up of two concentric tubes. First tube (12) comprises the puncture tip of the cannula, second tube (14) is mounted co-axially around first tube (12), and the two may be axially adjusted so as to withdraw the puncture tip of first tube (12) within second tube (14). The design allows latching of the cannula in the blunted position after use. Latching member (34) comprises spring (44) having spring end (54) which engages with step (56) upon retraction of the puncture tip into the blunted position. However, no means is disclosed for disengaging spring end (54) from step (56) and thus releasing the needle from the blunted position back into a sharpened position. The mechanism is located within the apparatus, so access during use is impossible. It would be advantageous to allow the healthcare worker to re-use the self-blunting needle under certain circumstances. For example, despite the presence of a flash chamber to aid in locating a vein, occasionally the first puncture of the patient does not hit a vein and the needle must be re-inserted. During xe2x80x9cintermittent administration,xe2x80x9d the user will use the same syringe to withdraw doses from a supply vial and administer them, several times.
It would also be advantageous to provide self-blunting needles which efficiently utilize the needle itself for fluid flow and which do not combine the function of blunting apparatus and catheter.
It would be advantageous to remove the possibility of accidental bumps or jostles changing the blunt or non-blunt configuration of the needle. It would also be advantageous to provide automatically self-blunting apparatus.
The present invention provides a needle assembly comprising a needle member comprising a needle cannula mounted in a housing, the needle cannula comprising a puncture tip and comprising a needle passageway extending substantially lengthwise through the needle cannula, and a blunting member comprising a blunting probe, the blunting probe comprising a blunt end, the blunting probe being disposed telescopically within the needle cannula while permitting flow through the needle passageway, the needle assembly being movable between a sharpened configuration in which the puncture tip of the needle cannula is exposed and a blunted configuration in which the blunt end of the blunting probe blunts the needle assembly. There is also a releasable locking means for releasably locking the needle assembly in the blunted configuration.
According to one aspect of the invention, the housing may define a chamber in fluid communication with the passageway of the needle cannula, and the releasable locking means may be located inside the chamber. In an alternative embodiment, the releasable locking means may be located outside the chamber. The housing may further define an open channel within which the releasable locking means is disposed.
According to another aspect of the invention, the releasable locking means may comprise a movable detent and a stay against which the detent may bear when the needle assembly is in the blunted configuration. The detent may be movable between a locking position in which it prevents the needle assembly from moving to the sharpened configuration and an unlocked position which permits the needle assembly to move to the sharpened configuration.
This invention also provides a needle assembly comprising a needle member comprising a needle cannula mounted in a housing, the needle cannula comprising a puncture tip and comprising a needle passageway extending substantially lengthwise through the needle cannula, the housing defining a chamber in fluid communication with the passageway of the needle cannula, the housing further defining an open channel comprising a stay. There is a blunting member comprising a blunting probe mounted in a shuttle, the blunting probe comprising a blunt end and being disposed telescopically within the needle cannula while permitting flow through the needle passageway. The blunting probe is movable between a sharpened configuration in which the puncture tip of the needle cannula is exposed and a blunted configuration in which the blunt end of the blunting probe blunts the needle assembly, and one of the shuttle and housing comprises a movable detent, and the other comprises a stay. The detent is movable between a locking position in which it may bear against the stay and prevent the needle assembly from moving to the sharpened configuration and an unlocked position which permits the needle assembly to move to the sharpened configuration.
According to one aspect of this invention, the shuttle comprises the movable detent. Optionally, the detent may extend outside the housing. Also optionally, the detent further comprises a coupling site.
This invention further provides a needle assembly comprising a needle member comprising a needle cannula mounted in a housing, the needle cannula comprising a puncture tip and comprising a needle passageway extending substantially lengthwise through the needle cannula, the housing defining a chamber in fluid communication with the passageway of the needle cannula, the housing further defining a stay outside the chamber. There is also a blunting member comprising a blunting probe mounted in a shuttle, the shuttle carrying a movable detent, the blunting probe comprising a blunt end, the blunting probe being disposed telescopically within the needle cannula while permitting flow through the needle passageway, and being movable between a sharpened configuration in which the puncture tip of the needle cannula is exposed and a blunted configuration in which the blunt end of the blunting probe blunts the needle assembly. The detent is movable between a locking position in which it may bear against the stay and prevent the needle assembly from moving to the sharpened configuration and an unlocked position which permits the needle assembly to move to the sharpened configuration, and the movable detent comprises a coupling site for engagement by an accessory. Optionally, the housing may define an open channel and the stay may be disposed within the open channel.
This invention further provides an accessory-needle apparatus comprising a needle assembly as described above together with an accessory dimensioned and configured to engage and move the detent to the unlocked position when the accessory engages the needle member
The accessory may be selected from the group consisting of a catheter, a Y-line adapter and a medication vial.
According to a particular embodiment, a detent as described herein may comprise an oblique flange, dimensioned and configured such that when the coupling site engages the accessory, the detent moves to the unlocked position.
In another embodiment, this invention provides a safety needle assembly comprising (i) a needle member comprising a needle cannula, the needle cannula having a puncture tip and having a needle passageway extending substantially lengthwise, and further comprising an interior; (ii) a blunting member comprising a blunting probe having a blunt end and having a sharpened blood collection end suitable for insertion into a blood collection tube and having a blunting member passageway extending from the blunt end to the blood collection end, and further comprising a shuttle; and (iii) the blunting member being disposed telescopically within the needle cannula while permitting fluid communication from the needle passageway to the blunting member passageway, and being movable between a sharpened configuration in which the puncture tip of the needle cannula is exposed and a blunted configuration in which the blunt end of the blunting probe blunts the safety needle assembly, wherein the needle member and the shuttle are dimensioned and configured for releasably locking the safety needle assembly in the blunted configuration.
There is also provided a blood collection needle comprising a holder dimensioned and configured to receive therein at least one end of a blood collection tube and a safety needle assembly as described herein mounted on the holder comprising a needle cannula mounted in a housing, wherein the holder comprises means for moving the blunting probe between the sharpened configuration and the blunted configuration.
According to one embodiment of the invention, the means for moving may comprise a longitudinal slot in the holder and first and second locking regions extending therefrom and a transmitting sleeve slidably disposed within the holder. The sleeve may comprise a tab protruding from the holder through one of the slot and the first and second locking regions, and may further comprise a swiping ring dimensioned and configured to unlock the safety needle assembly when the tab is moved from a locking region to the slot, and to lock the safety needle assembly when the tab is moved from the slot to a locking region.
There is further provided, in an alternative embodiment of this invention, a needle assembly comprising a needle member comprising a needle cannula mounted in a housing, the needle cannula comprising a puncture tip and comprising a needle passageway extending substantially lengthwise through the needle cannula, and a blunting member comprising a blunting probe mounted in a shuttle wherein the shuttle is disposed in the housing. The shuttle comprises a body and a movable detent, the detent comprising a base, the body and the base each having an aperture therein, a base aperture having an outlet and a body aperture having a guide surface that is offset from but converges to the body aperture. The blunting probe is disposed telescopically within the needle cannula while permitting flow through the needle passageway, and is movable between a sharpened configuration in which the puncture tip of the needle cannula is exposed and a blunted configuration in which a blunt end of the blunting probe blunts the needle assembly. The housing defines a first shoulder thereon and the shuttle is dimensioned and configured so that the detent can engage the first shoulder when the apparatus is in the blunted configuration and the detent is in the locking position. The detent is movable between a locking configuration in which the base aperture outlet is aligned with the guide surface and a released configuration in which the base aperture outlet is aligned with the body aperture.
Optionally, the housing may define a groove providing a second shoulder against which the detent may bear when the arm is in the locking position and the needle assembly is in the sharpened configuration.
There is further provided, in yet another embodiment of this invention, a blunting member comprising a blunting probe mounted in a blunting member hub, wherein the probe has a blunt end and a blood collection end and a blunting member passageway extending from the blunt end to the collection end, the blunting member further comprising an interior. There is also a needle member comprising a needle cannula, the needle cannula having a puncture tip and with a needle passageway extending substantially lengthwise through the cannula, and the needle member further comprising a needle shuttle on which the cannula is mounted, the needle shuttle being disposed telescopically within the blunting member interior, the blunting probe being disposed telescopically within the needle cannula. The needle shuttle is movable between a releasably locked sharpened configuration in which the puncture tip of the needle cannula is exposed and a releasably locked blunted configuration in which the blunt end of the blunting probe blunts the needle assembly.